Control system for ordnance



Dec. 28 1926.

E. M. HEWLETT ET AL CONTROL SYSTEM FOR ORDNANCE l Original Filed Sept,

hVen-tors Edward M Hewlet-b, WalclQ W. Willaufcl,`

Dec. 2s, 1926. ,1,612,118 E. M. HEWLETT ET AL CONTROL SYSTEM FOR ORDNANCE Original Filed Sept. 27, 1921 6 Sheets-Sheet 2 n ao i lm/en-bors: Edward M.l-lewlebt @Waldo W. Willard,

q E. M. HEWLETT ET AL Dec. 28, 1926.

CONTROL SYSTEM FOR ORDNANCE 1921 GYSheets-Sheet 3 Original Filed Sept. 27,

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Dec. 28 1926.

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56 j so 5, f/z a l /22 es' b5 @Wed/@Aw aus Patented Dec. 28, 1926.

. UNiTED STATES PATENT OFFICE.

EDWARD M. HEWLETT AND WALDO wf WILLARD, OE SCHENECTADY, NEW YORK, AssIGNORs To GENERAL ELECTRIC COMPANY, A CORPORATION OE NEW YORK.

CONTROL SYSTEM FOR ORDNANCE.

Application Ilcd September 27, 1921` Serial/No. 503.545. Renewed May 211926.

lhis invention relates to control systems for ordnance and has for its object the provision of improved means whereby a gun or like device may be controlled from a remote l point.

, More specifically, this invention relates to a control system whereby a gun is automatica-lly. maintained fin a predetermined angular relation with respect to a remotev l0 telescope or sighting device. By means of one form of our invention, when firing from a ship the gun may be adjusted on a distant tar et and-kept O11 the target regardless of t e movements of the 'ship by holdingtlie telescope on the target, or on some fixed point of reference such as the horizon.

The gun is, in effect stabilized automatically in a predetermined angular position in altitude by holding the telescope in a predetel'lnined angular position in altitude.

In carrying out our invention, we employ a hydraulic motoi 'for adjusting the gun' and control the hydraulic motor from a remote telescope by means of a selfsynchronous system, now` known as the selsyn system, for transmitting the angular movement of the telescope. The angular movement of the telescope is transmitted with ,respect to the ship or other body on which it is mounted, and the resulting movement of the gun is also with respect to the ship or other body on which it is mounted. Movement of the telescope opens the control valve of the hydraulic motor, the resulting follow up movement of the hydraulic motor gradually closing the valve until when the gun' has followed the telescope, the valve is closed and. the gun brought to rest. By means of a hand-operated valve the ,hydraulic motor can be disconnectedV from the source of hydraulic supply Lso that the .gun can be adjusted independently of the automatic control means. le have also provided means for adjusting the angular' relation between the gun and\ the telescope and limit switches in the firing circuit of the gun which are automatically controlled in such manner that the gun can be fired only when it is in a predetermined angular relation with the telescope, and within predetermined limits of its angular movement.

For a more complete understanding of our invention reference should be had to the accompanying drawings in which Fig. 1 a simplified diagrammatic representation of ay control system for ordnance embodying our invention; Fig. 2 is a view in section of the connection between vthe synchronous receiver and the control valve-for Vthe hydraulic motor; Fig. 3 is a perspective view of the hydraulic motor; Fig. 4 is a simplified view partly in section of the hydraulic motor mechanism; Fig. 5 is a perspective View of a limit switch contact arm; Fig. 6 is an end view partly in section showing the hand control means; Fig. 7 is an elevation view partly in section of a limit switch; Fig. 8 `is an end view of Fig. 7; Fig. 9 isa plan View of Fig..7 Fig. 10 is a perspective view partly in section of the hand-operated valve control; F ig, 11 is a view in section ot the hand-operated valve;iFig. 12 is a diagrammatic view of the hydraulic motor; while Fig. 13 is a diagrammatic view of a modification of our invention.

lfVe .shall first describe a controlsystem for ordnance embodying our invention as a whole, and then point out more in detail the specific features of our invention.

Referring to Fig. 1 of the drawings, the gun B is controlled in elevation automatically in response to angular movement in altitude of a telescope A located at a convenient point of observation remote from the gun. The telescope is adjusted manually by means of handles 10 and 10 through a gear 1 1 actuated thereby which cooperates with a gear sector 12 on the telescope. The gun is actuated by a hydraulic motor 13 which is controlled automatically in response to movement of the telescope. A sultable gear train consisting of gears 14. and 15 connects rack 16 actuated by hydraulic piston 17 of the motor to a ,gear sector 18 on the ttor 20 in synchronism therewith. The transmitting generator is Operated at a suitable ratio with lrespect to the telescope by means ofspur gear 25 meshing with spur gear 11 and secured to the drive shat'26-of the generatoi'. Rotor shaft 27 of the receiving motor is in screw and nut relation in a quill 28 with an actuating rod 29 of an automatic control valve 30 for the hydraulic motor. Secured to quill 28 is a rack 31 which is connected through spur gears 32 and 33 to spur gear 14. The generator and motor are similar in construction, having single phase field windings 21 and 22 on their rotors and three phase armature windings 23 and 24 on their stators. The field windings are energized from a suitable source of alternating current supply, while like points of the armature windings are interconnected, n sels n transformer 130 which will be described hereinafter being interposed in the armature connections.

The operation of systems of this general character for the transmission of angular y rotors. When the rotors of the generator and motor are 1n the same angular positions -inovement is well known in the art.

Voltages are induced in the three-phase stator windings of the generator and motor by the single-phase field windings on the associated withrespect to their stators, the induced voltages in the armature windings are equal and opposite and consequently no current is set up in the armature windings. If the rotor of the generator is turned and held in its new position, the volta es no longer counterbalance, whereby equaiizing currents are caused to flow in the armature windings. The equalizing currents exert a'torque on the rotor of the motor causing itto' take up a position corresponding to the position of the generator rotor. Angular movement imparted to generator 19 is therefore reproduced by receiving motor 20.

When shaft 27 -is rotated by receiving inoL tor inresponse to movement of the tele- 4 sco ,7, valve30 is moved to the right or left,

as t e case may be, causing piston 17tomove the` gun in the direction in which the tele- "scope was moved.- Quill 28. is at the same time moved longitudinally through the gear train eonn'ectings'pu'r gear 14 with rack 31 inthe direction to return valve 30 to closed position.. Motor 20 is'mounted on a suitable isupport 20 (Fig. 4) 'attached to quill 28 so as tomove therewith. When the gun has followed the movement of the telescope, it is brought to rest. by the movement of valve 30 to closed sitiolk The hy raulic liquid, which may i 'Y water, is supplied'at constant ressure tothe hydraulic motor by drivenby an electric motor 35.

6,). is connected to the hydraulic motor through a suita 'le lump 1 umP pipe .36, the hydraulic liquid being exhaust'- j edjroin lthehydraulic' motor through pipe to well o Mln `the vfiring circuit 39 of the 'gun is a switch 4Q, mounted in handle'lO and is closed bythe gperatoifwhen the telescope is on the "ent control of the gun. mountedin a casing 42 secured on the righttarget, a switch 41 governed by the position of quill 28, and a switch 42 governed by the position of valve 30. In the positions shown in the drawing, switches 41 and 42 are closed. Should the gun be elevated or depressed more than a predetermined 1amount with i'espect to the ship, switch 41 will be opened by one of cams 43 and .44 movable with the (uill 28, as the case may be. In this way, t e hydraulic 'mechanism is pi'otectcdfrom damaging shocks due to firing the gun when the driving piston 17 is near either limit of its stroke. The range of the angular movement of the gun in which it can be fired can .be varied as desired by adjusting the position of cams 43 and/44. Contact 45 of switch 42 is moved to openthe firing circuit when valve 30 is moved more than a predetermined amount in either direction from closed position. Switch 42 is therefore closed and the gun can be fired only when the gun is within a predeterminedangular relation with the telescope. Switches 41 and 42 are not indispensable parts lof our invention, since the system is obviously operable with# out them. These switches may be used, however, to rovide protection for the apparatus and to acilitate firing only at proper times. Referring toFig. 2 showing a section of 'uill 28, shaft 27 of motor 20 is connected t rough a universal joint 46 to .one end of a shaft 47v extending through the quill and rod 52 and nut 53 so that it is-biased lobjectl o this arrangement is to take up4 lost htly out 'of alinement with rack 31 byat s ring 54 underneath nut 53.,4 The motion between therack and driving gear 32 meshing therewith. Y, f v

ig. 3,. is shown the hydraulic motor 13 'in pers ective. -hydraulic cylinder-55 is a casing 56 contain- `ing the automatic valve 30, while attached- In F Sscured to the top vof the to the side of the cylinder is a casin 57 o containing-' abend-operated valve 458.-.` Fig. 10) 'providedwith an actuating handle A59.

By -means cyfjthe hand-operatedva/lve. the

hydraulic motor can be entirely cut off from the source of hydraulic supply for independhand end of valve casing`56.

Lima Swiieii 4211s Referring to Fig. 4, the shaft' 16 carry-l ingspur gears `14 and 15 andthe shaftv33 carryingspur gears 32 and Biaro journaled in a suitable frame or housingv 80, (Fig. 7 a

tiring circuit.

portion of which showing bearings Si and S2 for shafts 16' and 33 is shown in Fig. 7. Suit-able guides are provided in the housing for slidably supporting quill 28 and rack 16, and aprojcct-ion Htl (Figs. 3 and 4) forms a head for hydraulic cylinder and a support for the liydiaulic motoi'. The housing SU is secured to the carriage of the gun mount so as to maintain the hydraulic inotoi' and operating mechanism in operative relation to the gun. Spur gear 33 is made in two halves yieldably connected for the purpose of taking up lost motion'in the gear train.

'.lhe cross-sectiomil area of piston rod 17 of driving piston t7 is vequal to one. half the area. of the piston face. Hydraulic pressure is constantly applied to the reduced piston face, and by regulating the prcssui'e on the opposite face, the piston is moved to any desired position in a well known manner.

ltcfci'ring to Figs. 3, 4 and 5, the movable contact 45 of limit switch 42 is carried on a rod 6() which is supported in casing 42 so as to be longitudinally movable.

nient of valve rod 29 by means of a link 6l pivoted ona stationary arm 63 and pivot-ally attached at its ends to reds 2S) and 60. By means of a spiralspi-ing on rod 6i), cngaging contact 45 and casing 42', rod 6() is bia-sed toward the left to take up any lest motion in the linkl. Adjacent oppositie sides of contact 45 are pivotally mounted arms 63 carrying insulated contacts 64 cooperating with contact 45. The arms 63 are biased toward each other by a spring 65 attached thereto so that whenvvalve 3() in closed position the contacts 64 rest against opposite sides of contact 45 and close the lVhen contact 45 is moved in either direction upon movement of valve 30 from closed position, it moves away from one contact 64 and moves theoppos'ite contact 64 with it; The firing circuit is thus held open through switch 42 as long as the valve 3() is open more than a predetermined amount. A projection 66 on each arm 63 is engaged by contact 45fon the return movement and serves'as a positive' means in addi- `tien to the bias of spring 65 for returning the arms to tlieirinner positions. Suitable connection terminals 67 for contacts 64 are provided in thev .bottom of casing 42'. The terminals 67 are made accessible at all times by providing a skeleton supporting base for the casing. A projection 68 on each contact arm rests on an adjustable screw 69 extend-ing through the bottom of casing 42 and limit-ing the movement of the Contact arms toward eachother and hence the position ofcontacts 64. 'Screws 69 are accesvsible from the bottom of the casing for adjustment, whereby the range of movemertof luniversal joint 46 is a bevel The rod 6() is' moved longitudinally in response to movejusted to cause the tiring circuit to be opened through the contacts after a predetermined movement of the valve 2i() in either direction from closed position.

Valve rod 2i) is provided with a coupling 7() which can be loosened by unscrewing collar 7l to permit the right hand section to be turned by means of knurcd knob 72. rl`his arrangement provides a means for actuating the valve 3() independently of the telescope since longitudinal movement is imparted to the valve rod 29 when knob 72 is turned by reason of the threaded engagement of the valve rod with nut 49.- By turning knob 72 inthe necessary direction, valve 3() can be moved to cause the hydraulic in'otor to make the desired adjustment of the gun. hnob 72 is used, however, only in the initial adjustnient to bring the gun in parallel relation with the telescope. Y

lxeferring to Figs. 2. 4, and 6, adjacent gear 27 secured to thc drive shaft 27 of the selsyn motor 2t). A bevel gear 28" movable intoengagenient therewith is secured on one end ot a shaft 29 which is `supported at right angles to shaft 27 in a bearing 30 secured to the selsyn iiiotoi' support 20'. On the other end of shaft 292l is a hand wheel 32a. \As shown in Fig. 6, bearing 30a is provided with an opening 33 in which is a movable pin 34a. lhe lower end ot' pin 34 is'yieldahly held against shaft 29 by a. flat spring 35 secured to the bearing 30 and engaging the upper end of the pin. ()n the shaft 29d are two annular grooves.` The shaft can be moved longitudinally by means of the hand wheel to cause gear 28a to engage or disengage gear 27u as desired, and the annular grooves are so positioned that the gear 28"* is yieldably held in either posit-ioii by the engagement of pin 34" with one of them. `By means of this arrangement, the hydraulic motor can be readily controlled by hand in case of a failure of the selsyn system, and also in any case Where such control is desirable. It is contemplated that ordinarily the selsyn motor will be disconnected electrically from the generator when this hand control is used, although it need not necessarily be disconnected, since the torque exerted by the selsyn motor in opposition to movement of the hand Wheel Will not be prohibitive. When hand control is used, hand wheel 32 is pushed inwardly until gear 28a engages gear 27a. The hand wheel is then turned in a direction to give the desired movement of the gun, movement of the hand wheel being transmitted through gems 28a-and 27a to shaft 27` for the control of the hydraulic motor.

Referring to Figs. 4, 7, 8 and 9, limit switch 41 is mounted on the stationary suppoi-ting frame or housing 80. The llimit switch consists of two normally engaging llt) carries on its free end a projection 87. A

bar 88 lits slidably in the channel of member 85 and carries the two adjustable cam members 43 and 44. v The left hand end of bar 88 is secured by lne-.ms of a threadediuterdonnecting member 91 provided with n lock nut 92 to a projection 93 on the sup# porting base 20 for selsyn motor 20. It will be seen that bar 88 moves with uill 28, and when the quill is moved beyon a ce1'- 'tain predetermined limit in either direction, contact 84 is lifted by the engagement of' one of cam members 43 and 44 with projection 87 Ito open the firing circuit through switch 41. The limits 4oi Inovement of quill 28 within which switch 41 is closed can be varied by adjusting the position of cams 43 and 44. A cover 94 encloses the switch parts. Insulating bushings 95, 96, 97 and 98 are provided to support the conductors (not shown) connecting the contacts 83 and 84 in the firing circuit.

The hand-operated valve 58, as 4shown in Figs. 10 and 11, is cylindrical in form and rotatable to either one of two positions, automatic or hand, 'by means of the handle 59. The valve is provided with two transverse, parallel passages 100 and '101, oflwhich passage 100 is the larger. -A longitudinal passage 102 extends from the inner end of the valve to intersect with passage 101. In the valve casing 57 are two pairs of transverse alined passages 103, 103 and 104, 104` at right angles to each other. When the handle 59 is turned to automatic position, passages 104 and 104 are obstructed by the valve, while passages 103 and 103' are connected through assage 100. When the handle is in..han position the reverse is true, passages 103 and 103 being obstructed, and passages 104 and 104 open throughpassage 101. The inner end of the valve casing is closed by a plug' 105 against the inner end of whichl the valve is seated. In the inner end of the plug is' a depression 106fin alinement with passage 102 1n the valve. Portions ofthe edge of the lug are cut away to form ports-107 whic connect depression 106 with anan- 4nular chamber 108 in the valve casing. The

annularchamber'is dee er at its lower side "whereit is. connected t rough passage 109 liand position the ends of.' the cylinders are connected to ether and also connectedto exhaust 'througi passage 102, Vports 107, chamber 108 and passage 109. Passage 103 is connected to the pressure side of pump 34 throu h ipe 36 (see Fig. 1). Passage 103 lea s throughsJ check valve 111 (see Fig. .12) to an annular pressure chamber 112 inthe left-hand end of valve casing 56. For the sakeof clearness, in Figs. 3 and 10 the handle is shown in mid-position between automatic and hand position, althou h it is not contemplated that the handle will be in this position at any time during the operation of our invention.

l, The automatic drical, hollow, an has a central portion o'f reduced size as shown in Fi 12. .An actuating rod 29 extends loose y through the valve and is ri idly secured to the left end thereof in a p ug 113. Several holes 114 (onl one of which is shown) are provided in p u 113 so as to maintain a free opening throng the valve, whereby the ressure at the ends of the valve are balance The end bearing portions of the valve are provided with a fine helical groove 51 which permits` a slight leakageand overcomes any tendency of the valve to stick to its seat due to eater pressure on one side. By thus balancing the pressures, acting on it, the valveis maintained freely movable at all times. By means of a spiral spr' 115 on rod 29 attached at one end touplzu 113 and at the other end to the right-han end of the valve casin the valve is biased toward the right to t e upI lost motion.

In the valve casin 56 and connected to the valve chamber t rough suitable orts are two annular chambers, a ressure c amber 112 and an exhaust cham r 112. The pressure chamber is supplied through assage 103,-as revious described. mmunicating wit the ex 'aust cha'mber 112' are two passages 116 and 117, assage 116 y leads from a central annular c amber 118 in the valve seat through' a releif valve 119 and has for its object to relieve excessive pressures, in chamber 118, while passage 117 eads directly to the valve chamber at one end of the valve so that the ends of the valve are maintained at atmospheric pressure. The valve is constructed to have a slight ne ative ,lap to permita small amount of lea age when it'is in'closed position; this prevents the sudden application of pressure whlchwould otherwise result from closing the valve suddenly while the piston is in motion, and also makes the hydraulic motor very sensitive to small movements of the valve 30. 'It will be `observed that when the valve .is in the closed position as show in Fig. 12, this leakage takes lace from the pressure chamber 112 past va ve 30 to cham# lill drop in pressure is substantially the same at both points of leakage it will be observed that the pressure in chamber 118 will be, substantially one half the pressure of the supply source and consequently the piston 17 will be stationary. Under these conditions it is obvious that any movement, however slight, ofthe valve 30 will cause either an increase or a decrease of pressure in the lefthand end of the hydraulic cylinder which will result in movement of the piston.-

The variable pressure end of the hydraulic cylinder is supplied by .passage 120 from chamber 118. Constant ressure is applied to the other end of the .cylinder through passage 121 from passage 103. In opposite ends of the hydraulic cylinder are arcshaped grooves 122 and 122 (see Fig. 10). (roove 122 extends between the inner ends of passages 104 and 120, while groove 122 extends between the ends of passages 104 and 121.

ln each end of the. hydaulic cylinder is a slow closing valve arrangement consisting in the left-hand end of a passage .123 connecting passage 101 through an adjustable needle `valve 124 to the cylinder at a po-int. nearer the end of the cylinder than the opening of "passage 104` and in the rightliand end of a similarly arranged passage 122i and needle valve 12-1. 'lliesel passages intersect the cylindeiiat an angle and at points below the center line of the. cylinder so that openings 125 and .125' in the shape ol' an ellipse with one end Aflattened aie formed in the cylinder, the pointed ends being toward the vouter ends of the cylinder (seeFig. l0).

The. action of thel slow closing valves is as follows: Assuming that piston 17 is approaching the -right-handliinit of its travel and has covered groove 122 and the openings of passages 104 and 121,v` it Will be observed that the pressure in the end of the cylinder must. be relieved through passage 123 and needle valve 124 through passage 104', groove 122, and passage 121 against the pump supply. The needle valve is adjusted to a restricted opening to give a predetermined `slow movement of piston 17. As the piston covers the opening 125 of passage. 123 the outlet to the entrapped l.ydraulic liquid` is still more restricted.. Due to its shape the opening is covered at a gradually decreasing rate, which gives a tine. wire drawing effect as the pointed end of the opening is covered, thus gradually bringing the piston to rest without shock or strain on the mechanism. The piston is brought to rest ina silnilar manner. atthe left hand extreme of its movement. It is therefore impossibletobring the piston to rest suddenly through carelessness or otherwise at either extreme ofits movement. T hisl is a very importantfeature inasmuch as the hydraulic inotor-is geared to a heavy gun` the moving parts of which have great inertia.

Referring to F ig. 1 of the drawings. for the purpose of introducing range adjustnient between the telescope and the gun we have interposed a selsyn transformer in the armature connections between the transmitting generator 19 and the receiving motor 20. 'l` his selsyn transformer is described and claimed in our copending application, Serial No. 501,007, filed Sept. 15, 1921, assignedto the same assignee as this invention. 'It consists of two three-phase distributed armature windings 131 and'132, winding 131 being mounted on a stator member and winding 132 being rotatably mounted on a shaft 133 in inductive relation to the winding 131. Secured to the shaft 133 is a worm gear 134 in engagement with which is a worin 135 secured to the shaft of a handwheel 136. By means of the handwheel the winding 132 may be adjusted with respect to winding 131 to any desired angular position. A dial 137 calibrated in range is secured to shaft 1513, and cooperating with the dial is a stationary pointer 138. Like points of windings 131 and 23 are interconnected by conductors 139, 140 and 141. while like points of windings 132 and 24 are interconnected by conductors 139', 140', and 141.

It will be observed that when windings 13() and 132 are in corresponding angular positions, the voltages induced in the wind ing 23 ofthe generator are transmitted through the transformer in their true phase relation to the receiving motor 20.. Should winding 132 be displaced with respect to winding 131, the voltagesl transmitted to the receiving motor will be shifted in phase with relation to the voltages induced in winding 23 and in a direction depending on the directions of displacement of the winding 132. The motor 20 will therefore be caused to lead or lag witlrrespect to the generator 19 by an amount depending on the i amount of displacement given to the winding 132. 1n this manner the hydraulic operating mechanism of the gun canbe controlled independently of the telescope to give the gun the desired angular relation with the' telescope for the range of the target. The

The operation of oui` inventionis as follows: Vhen it is desired to control the gun from the telescope, the hand-operated valve 58 is moved to automatic position, as

plied from pump 34 through pipe 36, pastoward closed position throu h the sages 103, 100 and 103', through check valve 11'1 to pressure chamber 112; and from passage 103 through passage 121 to the righthand end of the hydraulic cylinder 55. With the automatic valve 30 in closed posipiston 17 is held balanced by reason of the pressure of the vhydraulic liquid entrapped at the left hand of the piston acting to counterbalance the ressure supplied to the right hand of the piston, the pressure of the entrapped liquid being one-half the pressure supplied .by thekpump. Assuming that the automatic valve 30 is moved to the right by selsyn' motor 20 iin 'response to movement of the telesco e, oi'. vof handwheel 136 when introducing t e range adjustment, in the manner previously described, the ports leading from the automatici valve chamber 118 to exhaust chamber-112 are uncovered, and the left-hand lend of cylinder 55 connected to exhaust through passage 120, chamber. 118, around the reduced portion of the automatic valve, through the ports to chamber 112', through passage 11G-and pipe -37 to the ump well 38.' Piston 17 is thereby cause to move to the let to adjust the gun at the same time moving valve 30 back ear mechanism previously descri -until w en vthe -predetermined. angular relation between the and the Atelescope has a aim been estab ished, the valve is close an 4driving piston 17 brought to rest. In the event that valve 30 is moved to the left, the ports leading' from pressure chamber 1,12 will beuncovered and hydraulic' pressure supplied around the reduced .portion of the valveto chamber 118, thence through passage .120 to the left-hand end of` cylinder 55. Piston 17 is thencaused to move tothe right until brought to rest by the moving ofvalve l30 Vto closedposition. i f

'Thering circuit switch 40 is closed by I the telescope operator when hefhas adjusted .the telescope onxthe target, Jand .limit switches 41 and 42 in the' firing circuit are controlled automatically, as previously described, so that when the telescope is on the target, 'and the gun in a predetermined angular relation with the' telescope and within a predetermined range of its angular movement, the tiring circuit is closed and the gun red.

The relief valve 119 is set to withstand a pressure somewhat greater than the pressure supplied by the hydraulic pump. The

unction of the4 relief valve is to cushion [the shock on the hydraulic mechanism due 'nu' to jump of the gun muzzle when the gun respect excessive pressure in the eft hand end of cylinder 55 being releived through passage 120, chamber 118, passage 116, and the relief valve to exhaust. At' the same time valve 30 moves sli htly to the left uncovering the ports lea ng from chamber 118 to pressure chamber 112. .The check valve 111 is provided to prevent this excessive pressure from being applied from chamber 112 through passage 103 against the hydraulic pump, andalso to revent the gun from squatting due Ato t e escape of liquid through passage 103 while the pressure in the variable end of the cylind'erL is higher than the operating pressure of the pump due to the very greatly unbalanced weight of the gun during recoil." Movement of piston. 14 to the yright due to downward whip of the gun muzzle is' cushioned, v

however, directly in the h draulic motor, since the pressure generate in this'case 'is notgreat enough to endanger the hydraulic su 1y s stem. Y

Iliould it be desired to control the positionl by the usual manually operated or o manually controlled means independently! of the telescope, the hand-operated valve is 'turned to hand position: Inthis position ofthe valve the ends of cylinder 55 are connected together through. assa es 104 and 104, and passage 101 in t e vva ve, andl also to exhaust through passage 109. Piston 17 is, therefore, freely movable to permit the gun to be moved to any desired angular position.

In Fig.v 13 of the drawings, We have shown a modification of our invention in which the range adjustment is made by mechanical means fon the telescope. The telescope A is piv'otally mounted on the gear sector 12 "to move about the fixed transverse horizontal axis 145 voit the 'gear sector. Secured tothe telescope is a' worm geary sector 146 in.

engagement with which is a worm 147 carried .b a shaft 148. The shaft- 148 is rotatab mounted on the gear sector 12 and is held a inst 'longitudinal movement with creto by any suitable means not shown. The worm 147 can be rotated to elevate or depress the 'telescope about its axis 145. with relation to gear sector 12 by.-

handwhecl 149 until the range of the target is indicated on 'dial 150 by the pointer 151 and then adjusting the telescope about its axis 145 until it is again on the target by moving gear sector 12 by means of handles 'and 10. In this case th'e desired angular relation between the gun and the telescope is made by adjusting the telescope independently of the gun and theigun given the necessary elevation by moving the gun and the telescope. in synchronism when the telescope is again broughton the target.

Various methods may be used in operating the system. vThe telescope may be held on the target or on some fixed point of reference, such as the horizon, the gun automatically following the telescope through the roll and pitch of the ship,-or the telescope may be held at a convenient elevation and the gun fired when the telescope rolls on the target. Although we have shown our invention applied to the control of guns in altitude, it is contemplated that the'invention can also be applied to the control of guns in azimuth. Obviously any suitable self-synchronous system for the transmission ot' angular movement may be used for transmitting the movements of the telescope.

In accordance with the provision-'. of the patent statutes` we have described the'principle of operation of our invention togetherl with the apparatus which we now'consider to represent the best embodiment thereof, but we desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What we claim as new and desire to secure by Letters Patentot the United States, is:

1. A system ot' ordnance control comprisingI n gun, hydraulic operating means for the gun, a control valve for the hydraulic voperating means, a sighting d vice remote from the gun, operating means tor said control valve responsive to movement of the sighting device. and a movable support for said operating means .responsive to movementotl the gun whereby said valve is differentially controlled so as to maintain a predetermined angular relation between the gun and the sighting device.

2. A system of ordnance control rompi-ising a gun, hydraulic operating means for `the gun, a control valve 'for the hydraulic o ieratino means a sight-in device remote l rn from the gun, operating means for said cony trol valve responsive to movement of the sighting device. a'slidable support for said operatingmeans, a rack carried b v said support and a gear train connecting said rack to the gun. whereby said valve is differentially controlled` so as to maint-ain a predetermined angular relfation between. the gun and the sighting device.

3. A system ot ordnance control comprising a gun, operating means for the gun, a sighting device remote from the gun. a system of control associated with said sighting device and saidv operating means, a tiring circuit for the gun. and a switch' in said tiring circuit automatically controlled in accordance with the angular position of the gun, so that the tiring of the gun is limited to a predetermined range of its movement.

4. A system of ordnance control comprising a gun, hydraulic operating means for the gun, a control valve for the hydraulic operating means, a sighting device remote from the gun, a system of cont-rol assfxiated with said sighting device and said control valve. a firing circuit for the gun, and a switch in said tiring circuit automatically controlled to maintain the tiring circuit open when the gun is in a predetermined extreme of its angular movement in either direction. 5. A system of ordnance control comprising a gun, a hydraulic motor for operating said gun comprising a driving piston, a valve` for controlling said piston. a sighting device remote from the gun, means responsive to the position of the sighting device for controlling said valve, a vtiring circuit i'or the gun, a'switch in said tiring circuit, and means responsive to the angular position of the gun cooperating with .the switch so as to maintain the firing circuit open when the piston is near either limit. of its movement.

6. A system of ordnance control comprising in combination with a gun, a hydraulic motor operatively connected to the gun, an automatic control valve for said motor, a source of hydraulic supply for said motor. a sight-ing device remote from the gun, a system of control associated with said sight-- ing device and said automatic valve` and av hand operated selective valve in series with for automatic operation under fthe control of said sighting device and to another position to shut ofi the hydraulic supply and connect the hydraulic motor to the exhaust.

7. A system of ordnance control comprising in combination with a gun, a cylinder, a hydraulic driving piston in said cylinder operatively connected to the gun, an automatic control valve for said piston, a sighting device remote from the gun, a system of control associated. with said sight-ing device and said automatic valve, a source of hydraulic fluid pressure supply, a pipe connecting said source with said automatic valve, a selective valve in said pipe, and ports leadingfrom the ends of said cylinder to said selective valve, whereby when said selective valve is turned to admit fluid through said pipe said ports are closed. and when turned to shut o tt' the fluid supply'said ports are connected to exhaust.

8. A system of ordnance control comprissaid automatic valve movable to one position lill ing a gun, a sighting device remote from the gun, a transmittinggenerator actuated thereby, operating means for said gun, a receiving motor for controlling the same, alternating current field and armature windings fo`r said motor and generator, and electrical connections between said armature windings whereby the motor is caused to be in synchronism with the generator.

9. A system for ordnance control comprising a gun, a sighting device remote from the gun, a transmitting generator actuated thereby, hydraulic operating means for said gun, control means for said hydraulic operating means, a receiving motor for actuating the same, alternating current field and armature windings for said motor and enerator, and electrical connections for e ua lzing currents between said armature win` ings whereby the motor isV caused to be in synclironsm with the generator.

10. A system of ordnance control comprising a gun, a. sighting device remote from the un, a transmitting generator actuated therey, a hydraulic motor for operating said gun, a control valve for the hydraulic motor, a receiving motor for actuating said control valve, alternating current field windings for `said motor and generator, a source of/alternating current supply for said field windings, polyphase armature windings for said motor and generator, and electrical connections between said armature windin s whereby the motor is caused to be in sync ronism with the generator.

11. A system of ordnance control comprising a gun, a sighting device remote from the gun, a transmitting generator-actuated thereby, operating means for the gun, a receiving motor associated with said gun, differential control means for said operating means responsive jointly to movement oithe gun and the receiving motor, alternating current field and armature windings for said motor and generator, and electrical connections between said armature windin whereby the motor is caused to be in sync ironism with the generator-and maintain a predetermined angular relation between the gun and the sighting device.

12. A system of kordnance control comprising a gun, operating means Vfor the gun,

'a sighting device remotevfrom the gun, an

electrical system 'of control associated with said sighting device and said operating means, and electrical means interposed in said system of control forintroducing changes in angular relation between the gun and the sighting device.

' 13. A system of ordnance control comprising a gun, operating means for the gun, 'a sighting device remote. from the gun, an electrical system of 'control associated with said sighting device and said operating means, and electrically inductive means ining a gun, a sighting device remote from the' gun, a transmitting generator actuated thereby, operating means for the gun, a receiving motor for controlling said operatmotor being reing means, said receivin the generator so sponsive to movement o as to maintain a definite angular relationy therewith, and means interposed in the electrical connections between said generator and motor for controlling said angular relation.

16. A system of ordnance control comprising a gun, a sighting device remote from the gun, a transmitting generator actuated thereby, operatino'l means for said gun, a receivin" motor lfor controlling the same,

alternating current field and armature windings for said motor and generator, electrical connections between said armature wind` ings whereby the motor is caused to be in synchronism with the generator, and means interposedv in said connections for controlling the synchronous relation between the motor and generator.

17. A system of ordnance control com- Aprising in combination with a gun', a hydraulic motor operatively connected to said gun, a control valve for said hydraulic motor, means permitting leakage between the valve and its seat whereby said valve is maintained freely movable, a sighting device remote from the gun, and operating means for said valve responsive to movement of said si hting device.

18. system of ordnance control comprising in combinationVv with a gun, a h draulicmotor operatively connected to t e gun, a cylindrical control valve .forsaid hydraiilic motor, said valve being providederipheral groove permitting leak-:f ydraulic fiuid between the valve with a age of and its seat whereby said val\'e is maintained freely movable, a sighting device remote from the gun, and operating means for said valve responsive 'to movement of said sighting device.

19. A system of ordnance control comprising in combination with a gun, a hydraulic motor operatively connected to the grin, a sighting device remote from the gun, and operating means for said valve responsive to movement of said sighting device, said `-'valve being arranged to permit leakage side of said piston of lesser area, a valve fory controlling the fluid supply to the other end ofv said cylinder to, control the movement of said piston, a sighting device remote from the gun, and a system of control associated Vwith said sighting device and said valve, said valve being arranged to permit leakage from -said source to said cylinder and from said cylinderto exhaust when the piston is at,rest whereby the piston is responsive to small movements ofsaid sighting device.

21. A system of ordnance control comprising in combination with a gun, a cylinder, a driving piston in said cylinder operatively connected to said gun, said piston having different pressure areas on its opposite sides, a source of hydraulic uidsupply, a connection between said source and said cylinder on the side of said piston of lesser area7 a valve for controlling the fluid supply to the opposite end .of said cylinder, Va seat for said valve provided with a chamber connected to said opposite end of the cylinder and with ports controlled by said valve connected to the source of hydraulic Huid supply and exhaust respectively, a sighting device remote from the gun, and .operating means for said vvalve responsive to move'- ment .of said sightingdevice, said valve bef ing arranged to permit leakage of fluid from said source to said chamber and from said chamber to exhaust when the piston is at rest whereby the piston is responsive grooved to permit leakage, a tubular'seat 4 for said valve, said seat being provided, with a chamber corresponding to the central portion of said valve and ports controlled by the end portions of said valve, a connection between said chamber and said cylinder on vthe side of said piston lof larger area, connections between one of said'ports and the source of hydraulic luid supply and between the other port and exhaust, a sighting ydevice rem/Ote from the gun, .and operating means for said valve responsive to movement of said sighting device, said valve being 'arranged to permit leakage of Huid from said source to said chamber and from said chamber to exhaust when the piston is at rest whereby the piston is responsive to small movements of said sighting device.

In witness whereof, we have "hereunto set our hands this V26th day of September, 1921. i l e EDWARD M. HEWLETT. WALDO W. WILLARD. 

